Edge looks like a PETG variant that has been formulated to be less droopy than normal PETG. It costs about 3-4x as much as normal PETG filament. Scaffold is a PVA variant that prints about as easily as PLA. Anyone tried these? Are they any good?

I haven't tried either personally, I've heard very good things about both.Edge is a polyester copolymer like PET, but it's supposed to have better printing characteristics than some of the more generic PET filaments (less stringing for one).

Scaffold is a modified PVA, the important part is that it's much less sensitive to sitting at temperature than standard PVA. PVA is a pain to print with because if it sits in a hotend at printing temperatures for too long it blocks the hotend, so you end up doing gymnastics in the GCode to drop the temperature of the unused nozzle to prevent that happening. RichRap seems to have a very high opinion of it and I'd generally trust his opinion.I don't have a printer set up for dual extrusion at the moment, otherwise I would be very interested in trying git.

According to E3D, you can't leave Scaffold in an active hot end for more than 15 minutes or it will turn into a non-extrudable gunk that can be very hard to remove. I can just imagine trying to drill that out of a Cyclops! Yuck!!!

I've had pretty good luck with HIPS filament as support for PLA. Breaks off easy enough.